A team of coders from Imperial College London and Cornell University has come up with a brand new solution for bitcoin network scalability, which uses trusted execution environment in the components of secure hardware.
The team consists of Joshua Lind, PhD Student at Imperial College London, Ittay Eyal, a post-doc in the Systems and Networking Group in the Department of Computer Science in Cornell, Peter Pietzuch, Associate Professor at Imperial College London, and Emin GĂĽn Sirer, professor at Cornell.
— Emin GĂĽn Sirer (@el33th4xor) December 22, 2016
According to the developers, the solution called Teechan can be implemented in bitcoin’s protocol straightaway and without any modification of the core code.
The developers insist Bitcoin suffers from a fundamental limit on how far it can scale. While the number of transactions sent per day has been growing exponentially since Bitcoin’s inception, the number of transactions the system can clear is firmly capped at 7 tx/sec under the best of circumstances, and at around 3.3 tx/sec with realistic transaction sizes.
â€śThis means that, for example, if Venezuela were to switch over to Bitcoin today, every adult would be able to conduct at most one financial transaction every 72 days. And on the latency side, every non-trivial transaction would incur at least an hour’s delay,â€ť they say.
The number of scalability solutions is exuberant. Increasing block size may be a reasonable stopgap measure, however, changing the blocksize does not appreciably improve latencies for confirmations. And a 2X or 4X increase in block size delivers at most a 2X or 4X improvement in throughput. Even a highly controversial 10X increase in block size would yield only one transaction per week for Venezuelans, still far short of the target, the developers say.
Another option one might find in efforts such as Bitcoin NG, ByzCoin and Hybrid Consensus (suggested by research groups including Teechan creators) is to change the protocol to construct blocks incrementally over time, avoiding centralization bottlenecks.
â€śQuixotically, the practitioner community has been reticent about adopting these techniques or even acknowledging their existence during scaling discussions, reportedly because these proposals require changes to the underlying protocol.â€ť
According to the developers, most practitioners have focused on off-chain scaling, through a technique known as payment channels. allow for efficient transactions in which two parties can engage in a large number of fund transfers off chain, only settling the net result on the blockchain. While this can potentially improve scale immensely, these protocols, also, require substantial changes to the underlying protocol.
â€śSpecifically, Lightning Network implementations are vulnerable to transaction malleability, whose current proposed fix, SegWit, has become mired in controversy, partly as a result of its implementation complexity.â€ť
â€śWe have developed a new scalability solution for Bitcoin, called Teechan. It is a new, practical, high throughput, low latency off-chain transaction protocol that can be deployed securely on the Bitcoin network, as it exists today,â€ť the developers say.
Teechan is similar in design to the Lightning Network, save for one crucial differentiating factor: it leverages trusted execution environments (TEEs), that is, secure hardware components found in recent commodity processors such as the latest batch of Intel CPUs with Software Guard Extensions (SGX).
According to the developers, the new solution’s key features include: